Welcome, Guest. Please login or register. Did you miss your activation email?

Author Topic: Why is SFML in Debugconfiguration so slow?  (Read 4864 times)

0 Members and 1 Guest are viewing this topic.

Ankou

  • Jr. Member
  • **
  • Posts: 52
    • View Profile
Why is SFML in Debugconfiguration so slow?
« on: April 04, 2008, 03:54:40 am »
Hi
I recognized that I have a about 15 times faster output when I compile in Release mode, so debug mode is way to slow to debug what I'm doing.
(about 530 fps when showing nothing in both mode, a really small map 32*32 px per tile and 20*15 tiles(always the same tile) has about 18 fps in Debug mode and about 275 fps in Releaseconfiguration)
Is there a way to speed it up?

quasius

  • Full Member
  • ***
  • Posts: 166
    • View Profile
Re: Why is SFML in Debugconfiguration so slow?
« Reply #1 on: April 04, 2008, 04:52:51 am »
Quote from: "Ankou"
Hi
I recognized that I have a about 15 times faster output when I compile in Release mode, so debug mode is way to slow to debug what I'm doing.
(about 530 fps when showing nothing in both mode, a really small map 32*32 px per tile and 20*15 tiles(always the same tile) has about 18 fps in Debug mode and about 275 fps in Releaseconfiguration)
Is there a way to speed it up?


Run it in release mode?  Debug is always slower.  Depending on what your doing, possibly much much slower.
What can you not debug at 18 fps?  You don't really need a silky frame rate to see if it's working.

Laurent

  • Administrator
  • Hero Member
  • *****
  • Posts: 32504
    • View Profile
    • SFML's website
    • Email
Why is SFML in Debugconfiguration so slow?
« Reply #2 on: April 04, 2008, 05:32:52 am »
Have you made a Window.OptimizedForNonOpenGL(true) call ?
Laurent Gomila - SFML developer

Ankou

  • Jr. Member
  • **
  • Posts: 52
    • View Profile
Why is SFML in Debugconfiguration so slow?
« Reply #3 on: April 04, 2008, 01:15:34 pm »
yes

@quasius: 18 fps in a small one layer map. There'll be more layers, bigger maps and some movement.

Avency

  • Full Member
  • ***
  • Posts: 113
    • View Profile
Why is SFML in Debugconfiguration so slow?
« Reply #4 on: April 04, 2008, 04:05:27 pm »
For a single map 18 fps seem to be too slow, even in debug mode, I was getting better speeds on my old computer with a Radeon 9200 and a Pentium 4 (always above 100 fps in debug).
(I assume that you use VisualStudio)
And this was non-optimized code rendering 16x16 tilemaps using sf::Sprite (somewhat slow when compared to custom OpenGL rendering).
Can you give any computer specs? If it is too slow, there is probably not much you can do.
If you have access to some good profiling tools, it may help you to optimize your rendering code.

quasius

  • Full Member
  • ***
  • Posts: 166
    • View Profile
Why is SFML in Debugconfiguration so slow?
« Reply #5 on: April 04, 2008, 04:07:10 pm »
Quote from: "Ankou"
yes

@quasius: 18 fps in a small one layer map. There'll be more layers, bigger maps and some movement.


Re bigger maps: That shouldn't make a big difference if your code is smart.  Are you culling off-screen objects?  If it's still slow, consider using some kind of quad-tree structure (dividing all objects in the map into "zones" so you don't even have to look at objects outside of your current "zone") instead of doing an on-screen test for every single object.  If your talking about ginormous maps where memory becomes a constraint, you will need to do some kind of streaming or make the maps smaller and link them.
Again, debug is supposed to be slow.  When I was working in professional game dev, I was working on an engine that effectively *didn't run at all* on debug.  It sounds like you're worrying about something that really isn't a problem.
If you really think your code is running too slow, the problem likely isn't SFML.  How old is your dev machine?  Are you running innefficent collision detection?  Did you do something stupid like pass an stl::vector by value in a critical loop?  Are you misusing stl::vector by constantly inserting/removing items to/from the middle?  Are you over-manipulating memory?  Anyone of these things can tank your FPS, so it's really hard to answer a question like "why is it slow?"
But again, it sounds like you really may have no problem at all other than not understanding how slow debug mode is.

Edit:  If you're really worried about this stuff, get a hold of and figure out vTune.  It can profile your code and tell you what's eating all the clock time.  You shouldn't need to worry about the 3DAPI side of things (which has it's own profiler apps) since SFML is taking care of that.